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.TH CURLOPT_DOH_URL 3 "18 Jun 2018" "libcurl 7.62.0" "curl_easy_setopt options"
.SH NAME
CURLOPT_DOH_URL \- provide the DNS-over-HTTPS URL
.SH SYNOPSIS
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DOH_URL, char *URL);
.SH DESCRIPTION
Pass in a pointer to a \fIURL\fP for the DoH server to use for name
resolving. The parameter should be a char * to a null-terminated string which
must be URL-encoded in the following format: "https://host:port/path". It MUST
specify a HTTPS URL.

libcurl doesn't validate the syntax or use this variable until the transfer is
issued. Even if you set a crazy value here, \fIcurl_easy_setopt(3)\fP will
still return \fICURLE_OK\fP.

curl sends POST requests to the given DNS-over-HTTPS URL.

To find the DoH server itself, which might be specified using a name, libcurl
will use the default name lookup function. You can bootstrap that by providing
the address for the DoH server with \fICURLOPT_RESOLVE(3)\fP.

Disable DoH use again by setting this option to NULL.
.SH "INHERIT OPTIONS"
DoH lookups use SSL and some SSL settings from your transfer are inherited,
like \fICURLOPT_SSL_CTX_FUNCTION(3)\fP.

The hostname and peer certificate verification settings are not inherited but
can be controlled separately via \fICURLOPT_DOH_SSL_VERIFYHOST(3)\fP and
\fICURLOPT_DOH_SSL_VERIFYPEER(3)\fP.

A set \fICURLOPT_OPENSOCKETFUNCTION(3)\fP callback is not inherited.
.SH DEFAULT
NULL - there is no default DoH URL. If this option isn't set, libcurl will use
the default name resolver.
.SH PROTOCOLS
All
.SH EXAMPLE
.nf
CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
  curl_easy_setopt(curl, CURLOPT_DOH_URL, "https://dns.example.com");
  curl_easy_perform(curl);
}
.fi
.SH AVAILABILITY
Added in 7.62.0
.SH RETURN VALUE
Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insufficient
heap space.

Note that \fIcurl_easy_setopt(3)\fP won't actually parse the given string so
given a bad DoH URL, curl will not detect a problem until it tries to resolve
a name with it.
.SH "SEE ALSO"
.BR CURLOPT_VERBOSE "(3), " CURLOPT_RESOLVE "(3), "
